I have 235 on my truck and getting 21 mpg empty. I was wondering that if i changed to 255's will I get better mileage? And if I do change, I know the speedometer will be off. Is there any thing I can do to make the speedometer read correct? (change the gear? or Computer) to make it read correct.
Thanks
Brian

 

21mpg empty I wouldn't change a thing as long as that is hand calculated and not using the overhead reading. Technically you should get better hwy mileage with a taller tire but not too large, the 255's or 265's would be as tall as I would go, but you can get more drag and resistance from the tread on a taller tire. You didn't mention your year or trans type, go top left and click the User CP and fill out your signature so we know what year and trans type you have. You can change the calibration for the speedometer with aftermarket devices like the smarty or take it to the dealership and they can do it for a fee, this is advice for a 2nd gen 24V engine though.

Good luck and welcome to the site.

 

I have a 2005 6 speed manual, 3:73 rearend. Everything is hand calculated. I think I'll call dealer tomorrow and see about the fee.

 

Don't buy larger tires expecting fuel mileage increases. You'll be disappointed more than likely. Don't ask me how I know this..... Some will claim better mileage, but in my case loss of 4 mpg going to 35's... FWIW